cc: m.hulme@uea.ac.uk, wagner@thames.iiasa.ac.at, kuszko@thames.iiasa.ac.at, Peter Whetton , Chris Mitchell date: Fri, 12 Feb 1999 12:02:02 +1100 from: Barrie Pittock subject: RE: Stabilization/mitigation scenarios workshop to: 'Nebojsa NAKICENOVIC' , Timothy Carter , shaheen@sdpi.org, emilio@ppe.ufrj.br, rik.leemans@rivm.nl, lindam@ucar.edu, Barrie Pittock , semenov@glas.apc.org, j.skea@psi.org.uk Dear Tim, Naki, et al., The description of the Workshop on stabilization/mitigation scenarios makes clear its WG3 focus on mitigation. Our concern in WG2 must surely be on climate and SL rise impacts of such scenarios. This is the key to answering my and Bob Watson's concern that we address the FCCC objective which requires identifcation of safe levels of GH gases. Of course, what this requires is that such stabilization scenarios actually be run in GCMs and the results evaluated as regards impacts. So, either the Workshop should re recommending running GCMs with stabilisation scenarios ASAP, or else looking at those few stabilisation scenarios that have actually already been run in GCMs, such as several we have done in CSIRO. What we need are a survey of what stabilisation runs have been run, and what results are available especially regarding global and regional patterns of climate change and SL rise beyond stabilisation of concentrations. It is probably too much to expect detailed impact assessments from them in time for TAR, but some broad inferences could be drawn based on climate and SL sensitivity studies. For example, what are the implications of a latent 1 or 2 extra metres of SL rise after 2100? - given economic discounting, technological adaptation, etc., does the international community care, and if so why? Maybe that is a key question for WG3 also?! It is certainly relevant to international and inter-generational equity. I suggest that irrespective of what comes out of said Workshop, the above is one of the tasks that we Chapter 3 authors will need to address. I will try to address this in outline at least in my contribution to the zero-order draft, but any suggestions of other existing stabilisation simulations which can be looked at would be welcome. A technical question is whether we have only upwelling-diffusion models to apply to long-term SL rise beyond 2100, or some more physically based model results - we really need some vertical integrations of the deep oceans from detailed ocean models to put these estimates on a sounder footing - although maybe the actual SL rise is not the issue, but more the principle that a lot of latent rise will be in the system. Obviously Naki or others from Chapter 3 attending the Workshop in Copenhagen should convey this concern, and see that it is transmitted to WG1. I am already doing that via my colleague Peter Whetton in the adjoining office, but there is other overlapping membership of WGs 1 and 2. Does that make sense to everyone? Regards, Barrie. Dr A. Barrie Pittock Leader, Climate Impact Group CSIRO Atmospheric Research PMB 1, Aspendale 3195, Australia Tel +61 3 9239 4527, Fax +61 3 9239 4688 email barrie.pittock@dar.csiro.au WWW: http://www.dar.csiro.au/res/cm/impact.htm "Far better an approximate answer to the right question which is often vague, than an exact answer to the wrong question which can always be made precise." J.W. Tukey as cited by R. Lewin, Science 221,636-639. > -----Original Message----- > From: Nebojsa NAKICENOVIC [SMTP:naki@iiasa.ac.at] > Sent: Thursday, 11 February 1999 21:35 > To: Timothy Carter; shaheen@sdpi.org; emilio@ppe.ufrj.br; > rik.leemans@rivm.nl; lindam@ucar.edu; barrie.pittock@dar.csiro.au; > semenov@glas.apc.org; j.skea@psi.org.uk > Cc: m.hulme@uea.ac.uk; wagner@thames.iiasa.ac.at; > kuszko@thames.iiasa.ac.at > Subject: Re: Stabilization/mitigation scenarios workshop > Importance: High > > Dear Tim and colleagues, > > I just wanted to inform you that I am planning to attend this workshop > and > hopefully make a presentation about SRES scenarios in the context of > mitigation. > > Regards, Naki > > At 10:25 AM 2/11/99 +0200, Timothy Carter wrote: > >Dear colleagues, > > > >I am forwarding a message from Neil Leary about a workshop that has > some > >relevance for Chapter 3 (especially recalling Bob Watson's comments > in > >Geneva that we should address stabilization scenarios). I would be > grateful > >if you could read this through and let me know if you are already > planning > >to attend the workshop. > > > >The enquiry from Neil (and Rob Swart of WG III) includes a suggestion > that > >WG I/WG II has a representative at the workshop who could describe > the > >relevance for/linkages to the needs of these two WGs. Clearly, issues > that > >might need to be pursued include: > > > >1. How do stabilization scenarios affect projections of future > climate and > >sea-level change? > > > >2. How do the socio-economic and environmental assumptions underlying > these > >scenarios differ from the SRES scenarios we are already working with? > A > >multiple century, post-2100 time horizon is obviously one aspect that > will > >be different. > > > >To Linda Mearns and Mike Hulme (Chapter 13, WG I CLAs): Perhaps one > member > >of our teams needs to attend to provide some insights into the > climatic > >implications of stabilization. > > > >Best wishes, > > > >Tim > >